The present invention relates to office furniture and, more particularly, to adjustable chairs.
A wide variety of chairs are available which are principally adapted to the office environment. Such chairs include adjustable features to adapt them to the particular user and the task involved. The users of the chairs may, of course, vary significantly in physical characteristics. Such chairs may permit the chair back to tilt with respect to the seat and the base. Vertical height adjustment of the seat may be provided. The chair back may be vertically adjustable with respect to the seat. In addition, provision may be made for adjusting the seat position relative to the base and/or relative to the back. Examples of prior task oriented, adjustable chairs including some of these features may be found in U.S. Pat. No. 5,007,678 entitled CHAIR BACK HEIGHT ADJUSTMENT MECHANISM, which issued on Apr. 16, 1991 to DeKraker; U.S. Pat. No. 4,478,454 entitled WEIGHT-ACTUATED CHAIR CONTROL, which issued on Oct. 23, 1984 to Faiks and U.S. Pat. No. 4,198,094 entitled WORKING CHAIR, which issued on Apr. 15, 1980 to Bjerknes et al.
The chair may also include a stop mechanism to limit tilting motion of the chair back with respect to the base or the seat. The stop mechanism may provide a variable stop which results in a variety of maximum tilt positions. In the alternative, the mechanism may lock the seat back in an upright position and/or in a variety of different angular positions and, hence, prevent all tilting action. Examples of chairs including variable stop or lock mechanisms may be found in U.S. Pat. No. 4,720,142 entitled VARIABLE BACK STOP, which issued on Jan. 19, 1988 to Holdredge; U.S. Pat. No. 4,494,795 entitled VARIABLE BACK ADJUSTER FOR CHAIRS, which issued on Jan. 22, 1985 to Roossien and U.S. Pat. No. 4,390,206 entitled SYNCHROTILT CHAIR CONTROL, which issued on Jun. 28, 1984 to Faiks et al.
A need exists for an improved adjustable chair which achieves seat and back angular adjustment as well as locking of the back in a cost effective and reliable manner.